/*
 * Subspace.cpp
 *
 * This source file is part of the FoundationDB open source project
 *
 * Copyright 2013-2018 Apple Inc. and the FoundationDB project authors
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

#include "Subspace.h"

namespace FDB {
	Subspace::Subspace(Tuple const& tuple, StringRef const& rawPrefix){
		StringRef packed = tuple.pack();

		this->rawPrefix.reserve(this->rawPrefix.arena(), rawPrefix.size() + packed.size());
		this->rawPrefix.append(this->rawPrefix.arena(), rawPrefix.begin(), rawPrefix.size());
		this->rawPrefix.append(this->rawPrefix.arena(), packed.begin(), packed.size());
	}

	Subspace::Subspace(Tuple const& tuple, Standalone<VectorRef<uint8_t>> const& rawPrefix) {
		this->rawPrefix.reserve(this->rawPrefix.arena(), rawPrefix.size() + tuple.pack().size());
		this->rawPrefix.append(this->rawPrefix.arena(), rawPrefix.begin(), rawPrefix.size());
		this->rawPrefix.append(this->rawPrefix.arena(), tuple.pack().begin(), tuple.pack().size());
	}

	Subspace::Subspace(StringRef const& rawPrefix){
		this->rawPrefix.append(this->rawPrefix.arena(), rawPrefix.begin(), rawPrefix.size());
	}

	Subspace::~Subspace() { }

	Key Subspace::key() const {
		return StringRef(rawPrefix.begin(), rawPrefix.size());
	}

	Key Subspace::pack(const Tuple& tuple) const {
		return tuple.pack().withPrefix(StringRef(rawPrefix.begin(), rawPrefix.size()));
	}

	Tuple Subspace::unpack(StringRef const& key) const {
		if (!contains(key)) {
			throw key_not_in_subspace();
		}
		return Tuple::unpack(key.substr(rawPrefix.size()));
	}

	KeyRange Subspace::range(Tuple const& tuple) const {
		VectorRef<uint8_t> begin;
		VectorRef<uint8_t> end;

		KeyRange keyRange;

		begin.reserve(keyRange.arena(), rawPrefix.size() + tuple.pack().size() + 1);
		begin.append(keyRange.arena(), rawPrefix.begin(), rawPrefix.size());
		begin.append(keyRange.arena(), tuple.pack().begin(), tuple.pack().size());
		begin.push_back(keyRange.arena(), uint8_t('\x00'));

		end.reserve(keyRange.arena(), rawPrefix.size() + tuple.pack().size() + 1);
		end.append(keyRange.arena(), rawPrefix.begin(), rawPrefix.size());
		end.append(keyRange.arena(), tuple.pack().begin(), tuple.pack().size());
		end.push_back(keyRange.arena(), uint8_t('\xff'));

		// FIXME: test that this uses the keyRange arena and doesn't create another one
		keyRange.KeyRangeRef::operator=(KeyRangeRef(StringRef(begin.begin(), begin.size()), StringRef(end.begin(), end.size())));
		return keyRange;
	}

	bool Subspace::contains(KeyRef const& key) const {
		return key.startsWith(StringRef(rawPrefix.begin(), rawPrefix.size()));
	}

	Subspace Subspace::subspace(Tuple const& tuple) const {
		return Subspace(tuple, rawPrefix);
	}

	Subspace Subspace::get(Tuple const& tuple) const {
		return subspace(tuple);
	}
}